1. Field of the Invention
This invention relates to a catalytic method for the preparation of N-alkylmorpholines. More particularly, this invention relates to a catalytic method for the manufacture of N-alkylmorpholines from a C.sub.1 -C.sub.4 primary alcohol and a feedstock selected from the group consisting of morpholine, diethanolamine and bis-aminoethylether. Still more particularly, this invention is directed to the use of a titania catalyst to which a minor amount of phosphorus has been thermally chemically bonded at the surface thereof in the form of phosphate linkages for the manufacture of N-alkylmorpholines from a feedstock selected from the group consisting of morpholine, diethanolamine and bis-aminoethylether by passing such feedstocks together with at least an equimolar amount of a C.sub.1 -C.sub.4 primary alkyl alcohol over a catalyst wherein the catalyst is composed of titania to which a minor amount of phosphorus (0.5 to 7 wt. %) has been thermally chemically bonded to at least the surface in the form of phosphate linkages.
2. Prior Art
The catalysts used in the practice of the process of the present invention are disclosed in Vanderpool European patent application Ser. No. 83,307,520.3 published Aug. 28, 1984, wherein they are disclosed as useful in promoting the reaction of ethylenediamine with ethanolamine to provide essentially linear polyethylenepolyamine reaction products. Minor quantities of cyclic products are also formed.
Warner U.S. Pat. No. 3,709,881 discloses a process for preparing N-alkylmorpholines by reacting diethylene glycol with an alkyl, dialkyl or trialkylamine in the presence of a hydrogenation catalyst such as a copper-chromium, platinum, palladium or nickel catalyst. A process for the production of N-alkylated cyclic alkyleneimines, such as N-methylmorpholine from cyclic alkyleneimines such as morpholine and an aliphatic hydroxyl compound, such as methanol using a SiO.sub.2 /P.sub.2 O.sub.5 catalyst, such as a catalyst consisting of 90 wt. % silicon dioxide and 10 wt. % phosphoric acid is disclosed in Dockner et al. U.S. Pat. No. 4,105,657. The use of a silica-alumina catalyst or an acidic metal phosphate, a phosphoric acid compound, a phosphorous acid compound, a phosphite ester, etc. to promote the conversion of a N-(substituted) diethanolamine to the corresponding N-substituted morpholine is disclosed in Brennan U.S. Pat. No. 4,117,227.